This invention relates generally to a method and apparatus for transferring fluid from a filling reservoir to a receiving tank. More particularly, the invention relates to a method and a portable apparatus for blowing gas, such as air, through one or more of the lines connecting the filling reservoir to the receiving tank to remove residual fluid from the lines before disconnecting them to prevent the release of odorous fluids.
Frequently, fluid materials must be transferred from a filling reservoir to a receiving tank either to fill the tank or to drain the reservoir. For instance, odorous chemicals are frequently transferred from a bulk storage reservoir to a rail car, then from the rail car to a tanker truck, and then from the truck to a local storage tank. Usually the chemicals are transferred by connecting a fluid transfer line from the outlet of the filling reservoir to the inlet of the receiving tank, and pumping the chemical through the transfer line from the filling reservoir to the receiving tank. During each transfer from one container to another, there is the opportunity to release some of the fluid, either as a liquid or as a gas. Even when fluid transfer from one container to another is successful, some residual fluid may escape when the transfer lines are disconnected from the containers. If the fluid is odorous, a release may be a nuisance.
Further, gas is typically vented from the receiving tank as it is filled thereby preventing pressure from building in the tank. If this gas vents to ambient, then vapor containing the transferred chemical may be released, causing a nuisance if the gas has an odor.